Written by Liz Highleyman
Hepatitis B and C have become leading causes of death and disability worldwide, as other major communicable diseases such as HIV/AIDS, malaria, and tuberculosis (TB) have come under better control, according to an analysis published in the July 8 online edition of The Lancet.
Experts estimate that some 150 million people worldwide are living with chronic hepatitis C virus (HCV) infection and 240 million have chronic hepatitis B virus (HBV). But the global burden of death and disability due to virus hepatitis is less well understood than that of HIV.
Jeffrey Stanaway from the University of Washington and colleagues used data from the ongoing Global Burden of Disease Study to estimate morbidity and mortality for acute viral hepatitis (the first 6 months of infection) and for cirrhosis and liver cancer caused by chronic viral hepatitis (long-term infection) in more than 180 countries from 1990 through 2013.
Hepatitis A and E cause acute, self-limited infection, while hepatitis B and C can become chronic; hepatitis D or delta only occurs in people who also have hepatitis B. Over years or decades chronic hepatitis B and C can cause serious liver disease including cirrhosis (scarring) and hepatocellular carcinoma, a type of liver cancer.
Stanaway’s team estimated mortality using natural history models for acute viral hepatitis infections (A and E) and the Global Burden of Disease Study’s cause-of-death ensemble model for cirrhosis and liver cancer due to hepatitis B and C. They did not include disability related to chronic hepatitis B or C before development of advanced liver disease, which they acknowledge as a limitation of the study.
- Between 1990 and 2013, global viral hepatitis deaths increased from 890,000 to 1.45 million — a 63% rise.
- Most of these deaths (96%) were attributable to hepatitis B and C.
- Years of life lost increased from 31.0 million to 41.6 million during the same period.
- Years lived with disabilities also rose, from 650,000 million to 870,000 million.
- Disability-adjusted life-years rose from 31.7 million to 42.5 million — a 34% increase.
- Hepatitis B and C accounted for more than 90% of disability-adjusted life-years related to viral hepatitis.
- Disability-adjusted life-years related to hepatitis A, in contrast, decreased significantly between 1990 and 2013, likely due to vaccination and improvements in water supplies and sanitation.
- By 2013 viral hepatitis was the seventh leading cause of death worldwide, up from the tenth leading cause in 1990.
“Viral hepatitis is a leading cause of death and disability worldwide,” the study authors concluded. “Unlike most communicable diseases, the absolute burden and relative rank of viral hepatitis increased between 1990 and 2013.”
They noted that deaths attributable to HIV, TB, and malaria have fallen over the past 20 years, while those due to viral hepatitis have risen. For example, an estimated 1.3 million people worldwide died from HIV/AIDS and 1.4 million died from TB in 2013, according to the authors.
Viral hepatitis is “unusual among leading communicable diseases because the distribution of morbidity is evenly divided between high-income and low-income settings,” they wrote. The viral hepatitis death rate was especially high in East Asia, where hepatitis B is endemic.
“[B]y contrast with tuberculosis, HIV/AIDS, and malaria, mechanisms to fund [viral hepatitis] interventions in the poorest countries are largely non-existent, except for individuals who are also infected with HIV,” they wrote in their discussion. “The small proportion of global health funding targeted at viral hepatitis is disproportionate to its importance as a major cause of death and disability. Our results suggest that an evolution in funding structures is required to accommodate the burden of viral hepatitis and allow effective responses in low-income and lower-middle-income countries.”
“Although there are effective treatments and vaccines for viral hepatitis, there is very little money invested in getting these to patients — especially compared to malaria, HIV/AIDS, and TB,” senior author Graham Cooke said in an Imperial College London news release. “We now have a viral hepatitis global action plan approved in May by the World Health Assembly, and we now need to implement it.”
JD Stanaway, AD Flaxman, M Naghavi, GS Cooke, et al. GS Cooke, The global burden of viral hepatitis from 1990 to 2013: findings from the Global Burden of Disease Study 2013. The Lancet. July 8, 2016 (online ahead of print).
K Wighton, Imperial College London. Viral hepatitis kills as many as malaria, TB or HIV/AIDS, finds study. News release. July 6, 2016.